At present, most of electronic paper books on the market are black-and-white screen electronic paper books using E-ink (Electronic Ink) technology. This kind of product has the characteristics of low energy consumption and simple display. Color display electronic paper books can also be realized by E-ink principle. However, in order to achieve full color display, it requires a color filter of complicated structure, which greatly reduces its image quality and brightness.
In the related art, most display devices use a backlight module as their light source to increase brightness. In a backlight module, generally, a light-emitting diode or a cold cathode fluorescent lamp tube is used as the light source. The light source is coupled to a display through a light guide plate. However, such light source has a large divergence angle, and the energy actually entering the light guide board is low, which results in a decrease of efficiency of the display device. In addition, the contrast is reduced due to crosstalk caused when the light enters the display.